1. Field of the Invention
Aspects of the present invention relate to a monopolar membrane-electrode assembly (MEA) of a fuel cell. More particularly, aspects of the present invention relate to a structure of a monopolar membrane-electrode assembly that allows ease of electrical connections between unit cells.
2. Description of the Related Art
Monopolar fuel cells have a plurality of cells that are formed on both sides of an electrolyte membrane and that are connected in series. A structure or structures to connect anode electrodes on a first surface and cathode electrodes on a second surface of the electrolyte membrane are disclosed in U.S. Publication Nos. 2003/0180594 and 2003/0198853, the disclosures of which are incorporated herein by reference.
An example of a related art current collector is disclosed in U.S. Pat. No. 6,410,180. The reference discloses a mesh type current collecting portion that is on each of the electrodes of the membrane-electrode assembly (MEA) and a conducting portion that connects the current collecting portions that are on both surfaces of the MEA. However, the related art current collector reduces the efficiency of the fuel cell due to an increase in the contact resistance between the current collecting portion and the electrode, and an increase in resistance caused when electrons freed at a catalyst layer move to the current collecting portion through a fuel diffusion layer of the electrode and a supporting body. Also, a contact resistance between the current collecting portion and the conducting portion may be high.